function boombox_is_registered() {

    $is_registered = get_site_transient( 'boombox_theme_registration' );

    $is_registered = apply_filters( 'boombox/is_theme_registered', $is_registered );

    // Verified, access granted.
    if ( ! ! $is_registered ) {
        return true;
    }

    // Check if required plugin for activation is installed and active
    if ( ! boombox_plugin_management_service()->is_plugin_active( 'envato-market/envato-market.php' ) ) {
        return false;
    }

    $is_registered = false;
    $purchased_themes = envato_market()->api()->themes();

    foreach ( $purchased_themes as $purchased_theme ) {
        if (
            ( 'boombox' === strtolower( $purchased_theme[ 'name' ] ) )
            && ( 'px-lab' === strtolower( $purchased_theme[ 'author' ] ) )
        ) {
            $is_registered = true;
            break;
        }
    }

    if ( $is_registered ) {
        $expire = 3 * DAY_IN_SECONDS;
        set_site_transient( 'boombox_theme_registration', true, $expire );
    }

    return $is_registered;
}